Highly branched (“dendritic”) macromolecules are known in polymer chemistry. These highly branched compounds have large number of reactive groups; an approximately spherical form and can incorporate guest molecules inside the macromolecules. More details on the highly branched macromolecules can be found, for example, in O. A. Matthews et al., Prog. Polym. Sci., Vol. 23, pp. 1-56, 1998.
Thus, by stepwise synthesis, structures with a very regular composition are obtained which are referred to as dendrimers. This mode of synthesis is multistage and complex. In general, it required protective group reactions and additional purifying operations after each stage, which makes synthesis not only time-consuming but also costly. The highly branched dendrimer end products are highly pure and in particular they are monodisperse, which means that all the macromolecules have the same molecular weight and there is no molar weight distribution (O. A. Matthews et al., Prog. Polym. Sci., Vol. 23, pp. 1-56, 1998, page 5).
Another group of highly branched compounds is the hyperbranched polymers, which unlike the dendrimers do exhibit a molecular weight distribution (O. A. Matthews et al., Prog. Polym. Sci., Vol. 23, pp. 1-56, 1998, page 5). Generally, hyperbranched polymers are obtained starting from ABn-type monomers (wherein n≧2) in a one-stage reaction, described for example in T. Emrick et al., Polym. Bull. (Berlin) (2000), 45 (1) pp. 1-7.
From the prior art it is known that dendrimers or hyperbranched polymers can be used as auxiliaries and additives in the preparation of polymeric materials, in order to obtain an improvement in the physical and chemical properties of the polymeric material. R. Mezzenga et al. (Compos. Sci. Technol. (2001), 612 (5), pp. 787-795) describes the use of dendritic hyperbranched polymers as modifiers for epoxy resins. Similarly, highly branched oligomers, which are disclosed in WO 00/22030, can be used for modifying epoxy resins. European Application EP-A 1 070 748 shows the effect of highly branched polyesters as flow agents and levelling agents in powder coating materials.
U.S. Pat. No. 6,093,777 describes dentritic hyperbranched polyesters as impact modifiers for thermo-setting resins. These dendritic macromolecules contain ester bonds, in combination with ether bonds. The disadvantage of these dentritic hyperbranched polyesters is the presence of the ester function. Due to the hydrolytic degradation in an acid or in an alkaline medium and/or the hydrolytic degradation of the ester function as a result of microorganisms, the lifetime of, the polyurethane elastomers or of adhesives made according to the U.S. Pat. No. 6,093,777 is very limited.